The article discusses how a digital twin model was created to monitor the structural health of buildings by combining a building information model (BIM) and a real-scene 3D model. The researchers developed a method to place sensors in buildings and monitor their data effectively. They reconstructed the BIM into smaller parts based on building components, aligned the 3D model with a transformation method, and mapped semantic information. The monitoring data from sensors were then stored in a database and integrated with the fused model. The researchers successfully tested this method by creating a digital twin model of the Nanjing Museum Old Hall, showing that the fusion process is feasible and useful for monitoring building health.